Could a filter retrofit disturb the pressure relationship of an isolation room?

Could a filter retrofit disturb the pressure relationship of an isolation room?

It can: the filter’s resistance adds to the pressure the system’s fan works against, and the label directs that it is not used where it would restrict airflow beyond the system’s specification; the pressure relationship of a room is set and verified by the people who run that system.

The label prints the rated airflow and the maximum face velocity, and it states: “Do not use where this filter would restrict airflow beyond the system’s specification.” and “The frame edges can be sharp. Improper installation can reduce airflow or damage the equipment.” Results in a building depend on the system, the airflow, and how well the filter fits its track. The label states where to use the filter: forced-air heating, ventilation and air-conditioning systems in homes, businesses and institutions that take its panel size and run at or below the rated airflow and maximum face velocity printed on it. The Terms of Use state that Site Content is not to be used to diagnose, treat, or make a patient-care or infection-control decision.

Source: NanoFlashing™ Air Filter label; C-POLAR — Terms of Use, https://cpolar.tech/terms/.

Reviewed on 21 September 2026.